Update README.md with improved importing for CDNs (#104)
Update README.md with improved importing for CDNs (#104)

* Update README.md

Ensure both unpkg and cdnjs are listed as CDNs, deprecate existing alias CDN reference in preference for best practice explicit version, and updated wording similar to React documentation.

* Update README.md with latest minor version for CDN imports

* Fix production unpkg URL

reactjs/prop-types,facebook/prop-types